Development of a sampling method for the simultaneous monitoring of straight-chain alkanes, straight-chain saturated carbonyl compounds and monoterpenes in remote areas
Development of a sampling method for the simultaneous monitoring of straight-chain alkanes, straight-chain saturated carbonyl compounds and monoterpenes in remote areas
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DOI：
10.1039/c0em00354a
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发表时间：
2011-04-01
影响因子：
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通讯作者：
Galloo, Jean-Claude
中科院分区：
文献类型：
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作者：
Detournay, Anais;Sauvage, Stephane;Galloo, Jean-Claude
研究表明，生物源化合物、长链次级化合物和长寿命人为化合物参与了污染地区和偏远地区有机气溶胶的形成。这项工作旨在开发一种主动采样方法，以监测偏远地区的这些化合物（即C6至C11的6种直链饱和醛; C9至C16的8种直链烷烃; 6种单萜：α-蒎烯、β-蒎烯、异松烯、柠檬烯、α-萜品烯和γ-萜品烯;以及5种芳香族化合物：甲苯、间二甲苯、Meta二甲苯、对二甲苯和邻二甲苯）。使用自动进样器SyPAC（TERA-Environnement，Crolles，France）以200 mL min（-1）流速将样品收集到多床吸附剂柱上。对于高达120 L的采样体积（标准混合物，环境温度，相对湿度为75%），未观察到突破。由于臭氧已被证明会改变样品（观察到90%的醛和高达95%的萜烯损失），因此已验证向系统中添加经过调节的二氧化锰（MnO 2）洗涤器（完全回收受影响的化合物）在50%相对湿度-RH下的标准混合物）。首先对样品进行热解吸，然后通过GC/FID/MS进行分析。该方法允许适当的检测限（从2 ppt的异戊烯到13 ppt的辛醛-36 L采样）和再现性（从1%的甲苯到22%的庚醛）。它已被成功地用于确定在冬季和夏季的测量活动在法国南部的一个偏远的站点的目标化合物（每天6个3小时的样品）的日变化。
Studies have shown that biogenic compounds, long chain secondary compounds and long lifetime anthropogenic compounds are involved in the formation of organic aerosols in both polluted areas and remote places. This work aims at developing an active sampling method to monitor these compounds (i.e. 6 straight-chain saturated aldehydes from C6 to C11; 8 straight-chain alkanes from C9 to C16; 6 monoterpenes: alpha-pinene, beta-pinene, camphene, limonene, alpha-terpinene, & gamma-terpinene; and 5 aromatic compounds: toluene, ethylbenzene, meta-, para-and ortho-xylenes) in remote areas. Samples are collected onto multi-bed sorbent cartridges at 200 mL min(-1) flow rate, using the automatic sampler SyPAC (TERA-Environnement, Crolles, France). No breakthrough was observed for sampling volumes up to 120 L (standard mixture at ambient temperature, with a relative humidity of 75%). As ozone has been shown to alter the samples (losses of 90% of aldehydes and up to 95% of terpenes were observed), the addition of a conditioned manganese dioxide (MnO2) scrubber to the system has been validated (full recovery of the affected compounds for a standard mixture at 50% relative humidity-RH). Samples are first thermodesorbed and then analysed by GC/FID/MS. This method allows suitable detection limits (from 2 ppt for camphene to 13 ppt for octanal-36 L sampled), and reproducibility (from 1% for toluene to 22% for heptanal). It has been successfully used to determine the diurnal variation of the target compounds (six 3 h samples a day) during winter and summer measurement campaigns at a remote site in the south of France.